Trouble with Compressor blowing Breaker

[Junkman]

</font><font color="blue" class="small">( Before running a new dedicated circuit to the compressor I would see if the motor could be run on 220 volts. Some motors are easily converted by moving a couple of wires on terminals inside a cover at the end of the motor. Doing this would drop your 15-amp motor current to about 8 amps making a 220 volt, 12 gauge, 20-amp circuit more than adequate. He could use the white wire for the other hot conductor and not change the wiring, but that would violate the National Electric Code and possibly cause insurance problems for him if there was an electrical fire. )</font>

I am quite certain that the motor could be wired for 220 use easilly by changing a few wires inside of the motor case, but the outlet can't be changed easilly because there are only a HOT, NEUTRAL, & GROUND in a 110 circuit. He would have to have 2 HOTS, a NEUTRAL & a GROUND to convert it to 220 outlet and is missing one wire. Hence he would have to run new wire to make the change and that would still make it a dedicated circuit.

 

[Inspector507]

No need for a neutral on a 220V motor. 3 wires is adequate.

 

[Soundguy]

I went thru something similar with our upright 15 year old 60 gallon 5hp air compressor in our shop. Started poping the breaker.. so I replaced the breaker.. that got us another few months.. then it popped a starting capacitor.. got another.. then it popped them again... carted the motor down to the rebuild shop and it had some shorted windings. New 5hp motor was 20 dollars cheaper than a campbel hausfield 60 gallon upright.. so we went that route... Has been working fine for months.

As a side note.. we plumbed the tank from the old compressor ( 120 gallons ) into the line, and once it gets pumped up in the morning.. they have air all day with less cycle time on the compressor.

Look at those caps.. see if they have been leaking...

good luck

Soundguy

 

[TheKid]

Since the wiring to the compressor has been pretty well covered here are a couple of other things that have caused me problems. A weak motor start capacitor will cause a motor to pull more current on start up. Is the new garage colder than the old one? Colder temps equal thicker compresser oil and harder starting. I had to move mine to the basement because it didn't like my unheated garage in the winter.

 

[Junkman]

</font><font color="blue" class="small">( No need for a neutral on a 220V motor. 3 wires is adequate. )</font>

How do you get 3 wires out of a 110 circuit. When I upgraded my service last year, I had to separate the neutrals from the grounds to meet the new codes that CT is using. I also had to use a special meter socket that had a bypass switch inside of it. Isn't all this part of the National Electric Code that every state follows???? Is it now proper to use the white wire as a HOT wire???? I know that it is in certain instances such as an air conditioner, but a air compressor?????? Does it matter if it is plugged into a receptacle or hard wired???
/forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif

 

[Inspector507]

Junkman,
The white wire, in a multi-conductor cable, can be used as a hot as long as it's re-identified by tape, paint or other approved means. It makes no difference whether it's hard wired or plugged in.

Black=HOT
White (re-identified)=HOT
Green/Bare=Ground

Voila........220V /forums/images/graemlins/grin.gif

The meter socket you had to use in your case was not a rquirement of the NEC®, but possibly necessary because of your local power company's rules.

 

[BillyP]

On a 110 receptacle, you have a neutral, hot and ground wire. On a 220 you have 2 hot wires and a ground. You can use 10/2 w/G for either one.

Is that what you were asking?

 

[BIGUN]

Junkman,

I was talking about running new wire and using a 220-volt, 20amp receptacle, which is different than a 110-volt, 20amp receptacle. You wouldn’t want 220-volts wired to a 110-volt receptacle for obvious reasons. You wouldn’t want to just wire the original circuit for 220 volts because then every receptacle on that circuit would be at 220 volts.

As Inspector507 has explained, 12/2 w/ground is all you need on this circuit, 2 hots and a ground. A neutral is only needed when you are going to tap 110-volts off the circuit as you do in your breaker panel. If it were a 3-phase motor, then you would need 4 wires, 3 hots and one ground.

The beauty of 220-volts is that the voltage drop percentage is less than on a 110-volt circuit. The actual voltage drop is the same on both, but it is a smaller percentage on the 220-volt circuit. A 5-volt drop on the 110 volt circuit is approximately 5% while it is only a little over 2% drop on the 220-volt circuit. This would be the case if the current draw were the same on both. Since the current will actually be half as much on the 220-volt circuit the voltage drop percentage will be even less.

 

[CTyler]

Don't know Just guessing here but Junkman may have been thinking of a 220v dryer circuit. This has two hots, neutral and ground. The neutral is used to supply 110v to the timer etc... A straight 220v on needs the two hots as stated previously.

 

[BIGUN]

As I discovered since moving to Oklahoma from Texas that there are two types of dryer plugs. My dryer has a 220-volt, three-prong plug. When I moved in here and got ready to plug it in, the receptacle was a four-prong type with 4 wires as you stated. Well since a new receptacle was cheaper than a new plug, I changed it out to the 3-prong type, abandoning the 4th wire. I am keeping the old receptacle, you never know when it may be needed. /forums/images/graemlins/wink.gif